People are generally aware of the most common causes of hallucinations, like schizophrenia and a really high fever. But lesser known are the more rare causes; here are six you probably haven't heard about.

AshleyMadison.com, a dating site that enables men and women to have discreet affairs, is making a new kind of headline after Eric Anderson, its chief science officer, admitted he’s working to get the site shut down.

Anderson, who is also a professor at the University of Winchester in the UK, presented his paper-slash-case during the annual American Sociological Association conference in San Francisco. Within the paper, Anderson outlined the conclusions he had while observing — or some would say spying on — the online conversations 100 married women aged 35 to 45 were having with potential partners.

These women, much to Anderson’s surprise, were not looking to have an affair because they were unhappy in their marriage. Instead, he found that 67 percent of his (small) sample were seeking an exclusive affair because they desired more romantic, passionate sex. Most women were even painting their husbands in a positive light. "Our results reflect not marital disharmony, but the sexual monotony that is a social fact of the nature of long-term monogamous relationships,” Anderson said in a press release. “The most predictable thing about a relationship is that, the longer it progresses, the quality and the frequency of sex between the couple will fade. This is because we get used to and bored of the same body."

That monogamy is problematic for some couples isn’t a novel idea. Dan Savage, a sex advice columnist and founder of the It Gets Better Project, regularly speaks out against the hardship of exclusive partnerships. “I acknowledge the advantages of monogamy when it comes to sexual safety, infections, emotional safety, paternity assurances,” Savage told The New York Times. “But people in monogamous relationships have to be willing to meet me a quarter of the way and acknowledge the drawbacks of monogamy around boredom, despair, lack of variety, sexual death, and being taken for granted.”

Laura Kipnis preached this same idea for quite a while before she released her book Against Love: A Polemic in 2003. Critics accused her of attacking monogamous marriage, the basis of which inspired a guest post on the The Guardian, though she wasn’t denying happy marriages exist. The numbers were simply on her side: A 50 percent divorce rate in the United States and a 1999 Rutgers University study that found only 38 percent of married couples were actually happy. Rather, Kipnis was arguing monogamy might not be worth the effort couples put in to maintain it.

The numbers today haven't waivered. The divorce rate in the U.S. hovers between 40 and 50 percent, while one 2010 study found six out of 10 adults were unhappy in their relationship, with four out of 10 admitting they considered leaving their partner.

However, what is problematic is Anderson's research. He might not be wrong to suggest negativity surrounding AshleyMadison.com is misguided, but his work is both, if we're being honest, biased and unethical. Time didn't even think Anderson was qualified to conduct such research in the first place.

Dr. John Grohol, the CEO and founder ofPsych Central, found that the chance of infidelity rises as much as 25 percent over the course of an entire relationship. And it's a statistic we’re not convinced is dependent upon a "dating site."